leetcode

Solution to some Leetcode problems written in C++

git clone git://git.dimitrijedobrota.com/leetcode.git

1162.cpp (1106B)

0 class Solution { 1 int n, m; 2 3 bool valid(int x, int y) { return x >= 0 && x < n && y >= 0 && y < m; } 4 5 public: 6 int maxDistance(vector<vector<int>> &grid) { 7 n = grid.size(), m = grid[0].size(); 8 queue<pair<int, int>> q; 9 10 for (int i = 0; i < n; i++) { 11 for (int j = 0; j < m; j++) { 12 if (grid[i][j]) { 13 q.push({i, j}); 14 grid[i][j] = 0; 15 } else 16 grid[i][j] = -1; 17 } 18 } 19 if (q.empty() || q.size() == n * m) return -1; 20 21 vector<int> offset_x{0, 0, 1, -1}, offset_y{1, -1, 0, 0}; 22 23 int res = 0; 24 while (!q.empty()) { 25 auto [a, b] = q.front(); 26 q.pop(); 27 res = max(res, grid[a][b]); 28 for (int i = 0; i < 4; i++) { 29 int x = a + offset_x[i]; 30 int y = b + offset_y[i]; 31 if (!valid(x, y) || grid[x][y] >= 0) continue; 32 grid[x][y] = grid[a][b] + 1; 33 q.push({x, y}); 34 } 35 } 36 37 return res; 38 } 39 };